Browsing by Author "Hsu, TL"

Now showing 1 - 7 of 7

A shield-based three-port de-embedding method for microwave on-wafer characterization of deep-submicrometer silicon MOSFETs
(2005-09-01)
Cho, MH
;
Huang, GW
;
Wu, LK
;
Chiu, CS
;
Wang, YH
A general three.-port S-parameter de-embedding method using shield-based test structures for microwave on-wafer characterization is presented in this paper. This method does not require any physical equivalent-circuit assumption for the surrounding parasitics of a device-under-test. We use one open and three thru dummy devices to remove the parasitic components connected to the gate, drain, and source terminals of a MOSFET. By shielding the lossy silicon substrate, the cross-coupling from port to port can be significantly mitigated, and thus, the parasitics of probe pads and interconnects at each port can be separately subtracted. The MOS transistor and its corresponding dummy structures fabricated in a 0.18-mu m CMOS process were characterized up to 20 GHz. Compared with the two-port cascade-based de-embedding method, the proposed three-port de-embedding procedure can further eliminate the parasitics associated with the dangling leg in the source terminal. The impacts of the accuracy of the de-embedding technique on device modeling and simulation are also discussed.
Extraction of substrate parameters for RF MOSFETs based on four-port measurement
(2005-06-01)
Wu, SD
;
Huang, GW
;
Chen, KM
;
Chang, CY
;
Tseng, HC
In this work, a new method for extracting substrate parameters of radio frequency (RF) metal oxide semiconductor field effect transistors (MOSFETs) based on four-port measurement is presented. A T-liked substrate resistance network is used and the values of all components in the cold MOSFETs were extracted directly from the four-port data between 250 MHz and 8.5 GHz. The output admittance Y-22 can be well modeled up to 26.5 GHZ based on the extracted substrate resistances and the other extrinsic capacitances extracted from an active device.
Hot-carrier effects on power characteristics of SiGeHBTs
(2004-06-01)
Huang, SY
;
Chen, KM
;
Huang, GW
;
Tseng, HC
;
Hsu, TL
This letter investigates hot-carrier (HQ effects on the power characteristics of Si-SiGe HBTs using load-pull measurements. We found that the output power, power gain, and linearity of Si-SiGe HBTs are degraded after HC stress. Under constant base-current measurement, the HC-induced power performance degradation is found to be much worse than that under constant collector-current measurement. The HC effects on the cutoff frequency, nonlinearity terms of base-current and collector-current, and third-order intermodulation (IM3) cancellation effect have been analyzed to explain the experimental observations.
Hot-carrier induced degradations on RF power characteristics of SiGe heterojunction bipolar transistors
(2004)
Huang, SY
;
Chen, KM
;
Huang, GW
;
Hsu, TL
;
Tseng, HC
Hot-carrier (HC) effects on high-frequency and RF power characteristics of Si/SiGe HBTs were investigated in this paper. We found that the small-signal current gain, output power, and power gain of Si/SiGe HBTs are suffered by the HC stress. With different bias conditions, the degradations of cutoff frequency and output power were found to be worse under constant base-current measurement than that under constant collector-current measurement. These phenomena have been explained by the change of the current gain, transconductance, and base-emitter resistance under stress.
Hot-carrier induced degradations on RF power characteristics of SiGe heterojunction bipolar transistors
(2005-06-01)
Huang, SY
;
Chen, KM
;
Huang, GW
;
Liang, V
;
Tseng, HC
Hot-carrier (HC) effects on high-frequency and RF power characteristics of Si/SiGe HBTs are investigated in this paper. By using the two-tone load-pull measurement, we find that not only the cutoff frequency, but also the output power performances of Si/SiGe HBTs are suffered by the HC stress. In this work, S-parameters and intrinsic elements of an equivalent hybrid-pi model were used to validate the HC effects on high-frequency characteristics. With different bias conditions, the degradations of cutoff frequency, power gain, and linearity are found to be worse under constant base-current measurement than that under constant collector-current measurement. The HC-induced degradations on the current gain, transconductance, and ideality-factor of base and collector currents are analyzed to explain the experimental observations.
Linearity and power characteristics of SiGeHBTs at high temperatures for RF applications
(2005-07-01)
Chen, KM
;
Peng, AS
;
Huang, GW
;
Chen, HY
;
Huang, SY
In this paper, the power gain, power-added efficiency (PAE) and linearity of power SiGe heterojunction-bipolar transistors at various temperatures have been presented. The power characteristics were measured using a two-tone load-pull system. For transistors biased with fixed base voltage, the small-signal power gain and PAE of the devices increase with increasing temperature at low base voltages, while they decrease at high base voltages. Besides, the linearity is improved at high temperature for all voltage biases. However, for devices with fixed collector current, the small-signal power gain, PAE, and linearity are nearly unchanged with temperature. The temperature dependence of power and linearity characteristics can be understood by analyzing the cutoff frequency, the collector current, Kirk effect and nonlinearities of transconductance at different temperatures.
RF MOSFET characterization by four-port measurement
(2005-05-01)
Wu, SD
;
Huang, GW
;
Chen, KM
;
Tseng, HC
;
Hsu, TL
RF MOSFET's are usually measured in common source configuration by a 2-port network analyzer, and the common gate and commen drain S-parameters cannot be directly measured from a conventional 2-port test structure. In this work, a 4-port test structure for on-wafer measurement of RF MOSFET's is proposed. Four-port measurements for RF MOSFET's in different dimensions and the de-embedded procedures are performed up to 20 GHz. The S-parameters of the RF MOSFET in common source (CS), common gate (CG), and common drain (CD) configurations are obtained from a single DUT and one measurement procedure. The dependence of common source S-parameters of the device on substrate bias are also shown.